//输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字，
//例如，如果输入如下4 X 4矩阵： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 
//则依次打印出数字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.
#include<vector>
using namespace std;

class Solution {
public:
    vector<int> printMatrix(vector<vector<int> > matrix) {
        vector<int> temp;
        int col=matrix[0].size();
        int row=matrix.size();
        if(row==0||col==0)return temp;
        int left=0,right=col-1;
        int top=0,bottom=row-1;
        while(left<=right&&top<=bottom){
            //left to right
            for(int i=left;i<=right;i++)
                temp.push_back(matrix[top][i]);
            //top to bottom
            for(int i=top+1;i<=bottom;i++)
               temp.push_back(matrix[i][right]);
            //right to left
            if(top!=bottom)
            for(int i=right-1;i>=left;i--)
               temp.push_back(matrix[bottom][i]);
            //left to top
            if(left!=right)
            for(int i=bottom-1;i>top;i--)
               temp.push_back(matrix[i][left]);
            top++;left++;right--;bottom--;
        }
        return temp;
    }
};
